University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Consider Landscape Plantings When Using Deicing Salts

December 13, 2001

Even though we have yet to see significant snowfall, cleaning snow off streets, driveways, and sidewalks is expected in the coming weeks of winter. Deicing salts are part of the snow removal process, but keep in mind they can also damage landscape plantings.

Sodium chloride, a common deicing salt material, can damage vegetation in two ways. Plants may take up chloride from salts accumulating in the soil, leading to dieback and decline. Sodium from salts may also destroy soil structure, causing plant problems. Plant damage typically occurs within 30 feet of the roadway or parking lot where salts are used. Along high-speed roads, salt may also drift onto vegetation, causing clusters of twigs called "witches brooms" on deciduous trees or browning of evergreens.

In residential areas most salt damage to trees, shrubs, lawns, and other plantings is from salt accumulating in the soil. Deicing salts may either be deposited directly from plowing or through runoff as snow melts. If declining plants are located near sidewalks, roadways, or parking lots, consider deicing salts as one potential cause.

Deicing salt damage to plants depends on a variety of factors, including type and amount of salt, timing of application and species of plants. Consider less damaging alternatives to sodium chloride, although more expensive.

Examples include calcium chloride, magnesium chloride, or calcium magnesium acetate. Only apply the amount of salt needed to do the job. Mix salt with sand (for traction). Try to shovel or plow before salting. Also, consider where snowmelt goes and vegetation that may be affected when deciding where to pile snow.

Applying gypsum to lawns is sometimes suggested to counteract the salt, but good soil drainage is needed. Often areas near roads, sidewalks, and parking lots have poor soil drainage, limiting the effectiveness of the gypsum. Along highways, temporary screening may help prevent damage to trees and shrubs. Also be aware of areas prone to salt spray when choosing plant material for these sites so salt-sensitive species are not used.


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